Production of delta-epsilon-unsaturated carboxylic acids, their derivatives and the corresponding delta-valerolactones



. 2,905,698 PRODUCTION OF 11D CARBOXYLICACIDS, THEIR DERIVATIVES THE CORRESPONDING DELTA-VALERO- IACTQNES Wilhelm Friedrichsen, -,Ludwigshafen '(Rhine), Germany, assignor to Badische Anilin- & Soda-Fabrik Aktiengese'llschaft, Ludwigshafen (Rhine), Germany I No Drawing. Application April 23, 1956 SelialNO. 579,728

' Claims priority, application GermanyAprilZl, 1955 i V 7 Claims. ((1260- 3435) This invention relates to a process for :theproduction rof'dcita epsilon-unsaturated carboxylic acids, their derivatives and the corresponding de1ta-valerolactones.

Welrave found that :delta-epsilon-unsaturated carboxylic acids or their derivatives are obtained in a technically ad- United 1 States Patent,

DELTA-EPSIL'ON-UNSATURKT- .vantageous manner by reacting an olefine which bears a CH or CH group adjacent tothedouble linkage, at -a temperature above 150 C., with a compound of the general formula XCH -CH -Y in which X represents :a halogen atom ora hydroxy, alkoxy, aryloxy or acyloxy group, Y acarboxylic, tester, carbonamideor nitrile group and X and Y together may form a group -O-CO.

Suitable compounds of this general formula are for example beta halogenpropionic acids, hydracrylic acid, betaalkoxyand betaacyloxy-propicnic acids and their esters amideglbeta-propiolactone and the nitriles of bfilfi'.

halogen-, beta-hydroxy-, beta-alkoxyor beta acyloxypropionic acids.

Suitable olefines are in particular propylene and isobutylene.

When using propylene and beta-methoxypropionic acid methyl ester, the reaction may be formulated as follows:

When using free acids, as for example hydracrylic acid, lactones may be formed in addition to the delta-epsilonunsaturated carboxylic acids, for example:

/CHg H EH3 CHa-CH =0 2,905,698 Patented Sept. 22,"

400 parts nf'isobutylene with the addition of 400, parts of propionic :acid and 1 part of pyrogallol. .After distilling ofi unchanged initial :material, 48 parts of Z-methyl- --heXene-(.1.)-:acid-'( 6.) "and 40 parts of 4.4-dimethy1-deltavalerialactone formed from then-said acid by lactonization. The mixture boils at 115 to 130 C. at a-pressureoflzo torr. The mixture-may readily be separated :by'extraction with aqueous caustic. solutions The pure 2'm'ethy1- ihexene-(lj-acid-(fii) recovered by-acidifying thealkaline extract boils at atmospheric pressure at 223 to 225 C. and -4.4=dimethyl-delta=valerolactone at 225 to 230 C.

7 Example 2 v p 3.20 parts of beta-propionyloxypropionic acid heated with-400p parts of propylene with the addition of 1160 parts of propionic acid andi parrot pyrogallol in a silver-1ined autoclave for about 3-0 minutes at about 310 C. By fractional distillation of the reaction mixture there are obtained, besides unchanged initial materials, parts of .hexene-(1)-acid-(6) boiling at 202 to 205 -C. and 34 parts of .a residue of higher boil-ingpoint consisting of 4-methyl-delta-valerolactone and polymeric compounds. Similar yields "of heXene(1 )-'acid-(6) are obtained by using, instead of beta propionyloxy-propionic "acid, the equivalent amounts of beta-acetoxy-, beta-ethoxy or -betavpropoxy propionicacid or hydracrylic acid.

Example 3 loparts of 'beta-methoxypropionic acid methylesterare heated :forabout an hour at about 320 C. with 20 parts .ofisobutylene withan addition of 20 parts of propionic The reaction is preferably carried out in the presence of a solvent or diluent, such as hydrocarbons, organic acids, esters, ketones, ethers, alcohols and/0r water. To avoid polymerizations, the usual stabilizers, such as hydroquinone, pyrogallol or aminophenols, in amounts of about 0.01 up to about 5 percent of the reaction mixture are added. It is also advantageous to work in corrosionproof vessels. The most favorable temperatures lie at about 200 to 350 C.

The products obtainable according to the process of this invention are valuable intermediate products, in particular for softeners, plastics, textile assistants and pharmaceutical products.

The following examples will further illustrate this invention but the invention is not restricted to these examples. The parts specified in the examples are parts by Weight.

Example 1 225 parts of hydracrylic acid are heated for about 30 minutes at about 320 C. in a silver-lined autoclave with reaction mixture containing Z-methyl 5-cyano-pentene-( 1) which by sapom'fying yields about 7 parts of 2-methy1- hexene-( 1 -acid-(6 Example 4 Example 5 144 parts of beta propiolactone are heated in a silverlined autoclave with 350 parts of propylene with the addition of 288 parts of propionic acid and 1 part of hydroquinone for about 30 minutes at about 320 C. From the reaction mixture, by fractional distillation, there are obtained 70 parts of hexene-(1)-acid-(6) boiling at v 3 to 110 C. at apressure of 25 torr and 55 parts of ahigher boiling residue containing 4-methyl-delta-valerolactone and polymeric compounds.

I claim:

1. An improved process for the production of deltaepsilon-unsaturated carboxylic acids, their esters, nitriles and the corresponding delta-valerolactones which comprises heating a member of the class consisting of betachlor, beta-hydroxy, beta-lower-alkoxy and beta-loweralkyl-carbo-oxy propionic acids, their lower alkyl esters,

and nitriles and beta-propiolactone with an olefine selected from the class consisting of propylene and isobutylene at temperatures above 15 0 up to about 350 C.

in the presence of a stabilizer selected from the class consisting of hydroquinone, pyrogallol and aminophenol.

2. An improved process for the production of a mixture of hexene-(l)-acid-(6) and 4-methyl-delta-valerolactone which comprises heating a mixture of propylene,

propionic acid and beta-propionyloxy-propionic acid in the presence of a stabilizer selected from 'the class consisting of hydroquinone, pyrogallol and aminophenol for about 30 minutes at about 310 C.

3. An improved process for the production of a mixture of hexene-(1)-acid-(6) and 4-methyl-delta-valerolactone which comprises heating a mixture of propylene, propionic acid and beta-chlorpropionic acid in the presence of a stabilizer selected from the class consisting of hydroquinone, pyrogallol and aminophenol for about '1 hour at about 320 C.

4. An improved process for the production of a mix ture of hexene-(l)-acid -(6) and 4-methyl-delta-valerolactone which comprises heating a mixture of propylene,

propionic acid and beta-propiolactone in the presence of a stabilizer selected from the class consisting of hydroquinone, pyrogallol and aminophenol for about 30 minutes at about 320 C.

- auc s prises heating a member of the class consisting of betachlor, beta-hydroxy, beta-lower-alkoxy and beta-loweralkyl-carbo-oxy propionic acids, their lower alkyl esters and nitriles and beta-propiolactone with an olefine selected from the class consisting of propylene and isobutylene at temperatures above up to about 3.50? C. in the presence of propionic acid and a stabilizer selected from the class consistingfof hydroquinone, pyrogallol and aminophenol.

' 7. An improved process for the production of 2- 'methylhexene-(1) acid-(6) which comprises heating a mixture of beta-methoxy-propionic acid methyl ester,

'isobutylene and propionic acid in the presence of a stabilizer selected from the class consisting of hydroquinone, pyrogallol and aminophenol at about 320 C., saponifying the reaction product containing the 2-rnethylhexene-(1)-acid-(6)-methyl ester and the 4,4-dimethyldelta-valero-lactone formed by boiling it with at least the equivalent amount of about a 20 percent by weight caustic soda solution and acidifying the solution obtained.

References Cited in the file of this patent UNITED STATES PATENTS Ladd et a1 Sept. 25, 1951 

1. AN IMPROVED PROCESS FOR THE PRODUCTION OF DELTAEPSILON-UNSATURATED CARBOXYLIC ACIDS, THEIR ESTERS, NITRILES AND THE CORRESPONDING DELTA-VALEROLACTONES WHICH COMPRISES HEATING A MEMBER OF THE CLASS CONSISTING OF BETA CHLOR, BETA-HYROXY, BETA-LOWER-ALKOXY AND BETA-LOWERALKYL-CARBO-OXCY PROPIONIC ACIDS, THEIR LOWER ALKYL ESTERS, AND NITRILES AND BETA-PROPIOLACTONE WITH AN OLEFINE SELECTED FROM THE CLASS CONSISTING OF PROPYLENE AND ISOBUTYLENE AT TEMPERATURES ABOVE 150* UP TO ABOUT 350*C. IN THE PRESENCE OF A STABILIZER SELECTED FROM THE CLASS CONSISTING OF HYDROQUINONE, PYROGALLOL AND AMINOPHENOL. 